[R. Doug]

One other caveat to Rassy's post:  Only eject the Kindle from the "My Computer" screen.  Ejecting from the "Safely Remove Hardware and Eject Media" icon in the Windows Task Bar does not work completely as doing it this way does not allow the user to continue using the Kindle whilst it is tethered to the PC via the USB cable.

 

[R. Doug]

Good point, H. Claw.  Some USB ports will not accept devices with high power drains while other USB ports on the same computer will.  I believe it has to do with the hub to which that particular USB port may be attached.